1. Field of the Disclosure
This disclosure relates to an electric leakage circuit breaker, and more particularly, an electric leakage determination circuit for an electric leakage circuit breaker, capable of improving reliability of electric leakage detection.
2. Background of the Disclosure
An electric leakage circuit breaker refers to a circuit breaker which further has a function of detecting an occurrence of electric leakage and automatically breaking a circuit when the occurrence of the electric leakage is detected, in addition to functions of a typical circuit breaker.
In the electric leakage circuit breaker, an electric leakage determination circuit comprises a circuit section which determines an occurrence of electric leakage by acquiring an electric leakage detection signal on a three-phases alternating-current (abbreviated as “AC” hereinafter) circuit using a characteristic of a zero current transformer (hereinafter, briefly referred to as ZCT), which generates a secondary induced voltage upon the occurrence of the electric leakage, amplifying the electric leakage detection signal, and comparing the amplified value with a reference value. One example according to the related art electric leakage determination circuit will be understood by referring to the Korean granted Patent No. KR10-0991958 B1 which has been granted to the applicant of this application.
Also, in relation to the electric leakage determination circuit according to the granted Patent, an improved technology, which further employs a delay circuit section for preventing wrong determination of the electric leakage due to temporary noise, has been introduced.
However, the improved technology also teaches the configuration of determining the electric leakage and generating a trip signal after a lapse of a predetermined time of delay from an initial time point of exceeding a reference value according to the comparison result. Therefore, the technology is highly likely to bring about a malfunction of the determination circuit under an environment that noise is frequently generated due to various causes. This results in lowering operation reliability of the electric leakage circuit breaker.